Bath Time Sexy Time
by Anonymonimus
Summary: UF! Sans and UF! Papyrus have a bath. UNDERFELL


**The sequel no one but Kamitakai asked for! So if you like this, you know who to thank, haha**

 **...Can I even call this a sequel when it's in no way related to Bath Time Fun Time?**

 **Whatever.**

 **ENJOY!**

* * *

Sans had been jolted awake from a nap by a violent shiver. It crawled up his spine all the way to the back of his neck before spreading to the rest of his bones. The feeling soon passed and when it did, it left a warm sensation in its wake; one that had the core of him throbbing with an intense desire. He groaned as he fell back onto the sofa that had been serving as his bed and covered his face with his arms. He could feel the warm flush of a heat-induced blush radiating against his radiuses and ulnas. His heats had a habit of creeping up on him and striking fiercely at the most unexpected of times. There was never even the barest set up for Sans to brace himself and maybe warm Papyrus to the idea of satiating his needs on his terms. The latter skeleton preferred to be the one calling the shots at all times.

Sans groaned rolling onto his stomach, belatedly realising it wasn't the best of ideas. The friction sparked the ghost of pleasure which was enough to shatter any shred of decency he had been clinging onto. His mind immediately wandered to the option of humping against the cushion for satisfaction until Papyrus came back from his watch; and before he could toggle with the idea, debating the pros and cons, he was already at it. He slipped his legs on either side of the cushion, holding it firmly in between his femurs as he rutted against it with a growing desperation. Sans was always a slave to his lust.

"f-fuck…" he whined, canting his hips wildly, "yes…ahhn! yeah! like that! j-just like that!"

Before long, the smaller skeleton had his head thrown back as he moaned shamelessly as loud as he needed while pleasure began building up between his legs. He had already conjured himself an ecto cunt which was leaking with the need to ejaculate but also to be penetrated and fucked passionately. Naturally, Sans's mind wandered to his brother and the many times they had had sex. He could almost feel Papyrus holding his arms behind his back in a strong, almost painful grip while he pressed his skull into the mattress and took him like the whore he—

"Sans!" Papyrus shouted as he swung the front door open, "I'm h—what the fuck!?"

The taller skeleton had stopped dead in his tracks the second he happened upon Sans humping himself to an orgasm on their sofa. Sans obviously didn't feel the need to stop despite Papyrus's horrified gawking. In fact, he rejoiced at his brother's presence. Maybe he could find a way to get him to fuck him – stars knew he absolutely needed it.

"boss! you're – ahn! – you're home!" He managed to utter between moans, "i'm…mm _yeah_ —"

"You're in heat." Papyrus grimaced, covering his nose with his hand, " _Stars_! You absolutely reek of lust!"

Sans chuckled drowsily, reaching beneath his shirt to toy with his ribs. They always got particularly sensitive when he was in heat. "boss…fuck me."

Papyrus looked very annoyed with his request. "You rude, lecherous…" he grumbled and trailed off before decisively stomping over. He was pissed, but Sans didn't care much until he was pulled off the sofa.

"hey!" he whined at the manhandling. He would only accept it if Papyrus was going to fuck him, but it didn't seem that would be the case.

His brother began dragging him up the stairs despite his protests. Papyrus hauled him into their bathroom and forced him into the bathtub before dousing Sans with cold water. The latter flailed angrily, scrambling to get away from the cold only to be stopped by the taller skeleton.

"boss, what the fuck!?" Sans shouted.

"That'll teach you not to be such a slut to your heat." Papyrus growled belittlingly. "Learn to have more control. You're an embarrassment."

Sans glared at him before turning his nose up and pointedly looking away as he sank into the basing to sulk. "i don't understand why you're always like this with me on _my_ heats." He muttered.

"Maybe if you weren't so disgusting, I'd be nicer." Papyrus retorted, turning on the hot tap. "On that note," he continued, "How many fucking times did I tell you to _not_ hump the couch!? Cleaning your ectoplasm and cum is the most laborious thing in the world!"

"at least i had the decency to keep my pants on this time…" Sans groused, curling further into himself.

" _At least_." Papyrus repeated, rolling his eyes. "Speaking of, take them off. The rest of your clothes too."

"what? why?" Sans cavilled, "i don't want to take a bath!"

"Your clothes are filthy and _you're_ filthy. You don't have a choice in the matter." Papyrus indicated sharply. "Now do as I say."

Sans complained and protested beneath his breath as he begrudgingly complied with the demand. Papyrus always called the shots. Nothing was ever done without his approval and especially if it wasn't on his terms. Sans used to never care. Not having a choice in anything was fantastic – it required less thinking and less initiative. He could be all the lazier because his brother insisted on micromanaging everything. However, now that they were screwing religiously and were an exclusive item, having no choice on when and where and for how long they would fuck was both exhausting and frustrating – especially in the midst of heats.

"here." Sans muttered, extending his wet clothes to his brother.

Papyrus took them, folding them neatly then turning the bath tap off. Sans expected him to leave him be but, to his great surprise, the taller skeleton set the wet clothes aside and began stripping himself out of his battle body. Without so much as another word, he slipped into the tub with Sans and leaned against one end of the basin. Were they going to fuck? Sans really hoped so, but refused to get his hopes up too high. He knew Papyrus and it would be very unlike him to agree after explicitly having said no.

"Have you really no shame?" He asked, visibly unimpressed.

Sans grimaced and followed his gaze to the ecto cunt between his legs. "i'm in heat! what are you expecting?" he countered, "i don't have control over this!"

"Whatever. Turn around." Papyrus ordered dismissively.

The smaller skeleton couldn't help but blush as his mind strayed to less than pure thoughts. _Stars_ he wanted Papyrus to fuck him silly. He hoped it was what he intended to do the moment he had him facing his back. There was nothing more he wanted than to be shoved on all fours and plowed into like—

"Please get your mind out of the gutter." Papyrus groaned disappointedly. "You're really hopeless…"

"come on, boss…" Sans started. He could feel his pussy begin to tingle with excitement and arousal. "why would you come into this bath with me if not for that?"

"Because you're filthy and I can't count on you to clean yourself properly." Papyrus replied bluntly. "Now turn around so I can start and we can both get out of here as soon as possible."

Sans frowned at the honesty behind the answer. As much as it upset him, it was also probably a form of punishment. Stars knew that Papyrus got off on punishing him for whatever he deemed wrong, shameful, or unbecoming. Withholding sex during a heat was, however, the cruelest thing the taller skeleton had done to him thus far.

"fine." He complied.

The moment his back faced Papyrus, the latter grabbed him by the hips and pulled him closer. Sans yelped, nearly slipping, but also startled by the sparks of pleasure the contact earned him. Papyrus, on the other hand, offered no reaction and continued his ministrations as though Sans shouldn't be bothered by their proximity and yet lack of intimacy. He grabbed the bath sponge hanging in the toiletry basket on the wall and doused it with soap. Then he reached for Sans and began cleaning him. His movements were gentle but firm, carefully scrubbing the muck from the smaller skeleton's bones and rinsing the soap away until it was nearly sparkling clean. Knowing how annoyed his brother was with him, Sans struggled to keep any moans from escaping his mouth.

He was doing a great job until Papyrus abruptly moved to his ribs and applied far more force in his gestures. Sans gasped, clenching his teeth together in the nick of time to keep a moan from sounding. He tensed considerably as he fought the waves of pleasure that shot directly down to his pelvis and ecto pussy. He could feel it begin to lubricate with desire and anticipation.

"boss…" He eventually croaked when the pleasure was getting too much.

"You're an absolute mess." Papyrus chastised, but his tone was significantly lighter.

"y-you're teasing me…" Sans stammered, holding back a whine.

"No." The taller skeleton replied lowly, his hands dropping the sponge and moving down his body, "If I was…" he continued, his voice low and rumbling, "I'd be doing this…"

Sans jolted and moaned as he felt Papyrus's fingers abruptly penetrate him. The next thing he knew, the digits were rapidly pumping in and out of him and all Sans could do in response was lean back and moan. It wasn't as though he was unhappy with his predicament. He was actually ecstatic to have Papyrus finally pleasure him after all that begging and teasing.

"boss—" Sans whimpered, nuzzling his head in the crook of Papyrus's neck.

"Don't be a greedy slut." Papyrus warned, "It's what got me upset with you to begin with."

"but i need you…" Sans moaned, canting him hips in time with Papyrus's thrusts. "your fingers…they're not enough…"

"Stars…" Papyrus growled lowly, "You really _reek_ of lust…"

Sans was suddenly shove away. He nearly bonked his head against the edge of the tub but caught himself just in time to spare himself the dull pain. The skeleton glanced back agitatedly, wondering what the hell was wrong with his brother when his eyes caught sight of the bright red ecto cock Papyrus had summoned just for him. He could feel his pussy twitch in delight. The length was big and long, just the way he liked it.

"Sit on it." Papyrus demanded.

Sans scrambled back to his brother and wasted no time in straddling him. He took the cock with one hand and held himself on the tub with the other as he guided the tip into his entrance desperately. He cried out as he sank onto it, sighing at the familiar, addicting feeling of being penetrated. He couldn't wait to start thrusting frantically to reach the orgasm Papyrus had promptly interrupted when he yanked him from the sofa, but the moment he tried to do anything more, he was stopped.

"Ah, ah." Papyrus tsked, wagging his finger in front of Sans's face. "You're giving in to your greed again."

" _papy_ please…" Sans whined, urgently trying to thrust, "i need you to fuck me…fuck me so good, please…"

"No." Papyrus denied firmly. "You're going to fuck yourself on my dick _slowly_. I don't care how horny you are, you're going to learn to savour rather than mindlessly devour; understood?"

"y…yes…" Sans pouted.

As instructed, he slowly rose his hips and sank back down onto Papyrus's cock. Sans's body ached for a much faster pace, but whatever the taller skeleton said was his law. He had no other choice but to comply. The pleasure he earned from the leisurely speed was bare. Faint tingles of bliss throbbed in his bones, though most of it was stifled by his maddening yearning for more.

"Isn't this nice?" Papyrus asked and groaned, giving a small cant of the hips. All Sans could do was nod as he tried to find some way to increase the degree of pleasure. "Isn't it better this way?"

"do you…really want my honest opinion?" Sans snorted with a breathy laugh.

Papyrus frowned at him. "Still not satisfied?" he demanded dangerously. Sans gulped heavily, unsure how to respond to defuse the situation. Before he could utter anything else, the taller skeleton shifted their positions, pushing Sans against the opposite end of the tub as he loomed above. Suddenly, he began thrusting hard and fast just like the other had needed. A gurgle of startled moans erupted from his throat as he swung his arms around his brother's neck and held on tightly. The water in the tub splashed about madly, spilling onto the floor. "You like it better when I fuck you hard, hun?" Papyrus growled. "When I overwhelm you with bliss?"

"y-yes!" Sans cried. "oh _stars_ yes! ahh!"

"You're a dirty fucking whore, you know that?" Papyrus hissed lowly, snapping his hips harshly. The action elicited the degree of pleasure that always drove Sans mad – it was ecstasy mixed with delicious pain. "Explains why you won't stop moaning like a bitch."

"papy! oh! fuck! _fuck_!" Sans shouted, he was quickly reaching his climax and how could he not when Papyrus was being so merciless with him? "fuck me hard! i-i'm yours!"

"Cumming already?" Papyrus smirked, "How typical of you. You always finish so fucking quickly! Don't let me stop you!"

"papy! papy i'm so close!" Sans whined, frantically moving his hips to meet each and every of Papyrus's thrusts.

The feeling of the taller skeleton's cock pushing so deep into him, nearly all the way, was absolutely addicting. If there was one sin he would never be able to recuperate from, it was lust – not when Papyrus knew how to fuck him so good. The latter kept thrusting into him with great vigor. The pleasure he felt coursing through his bones quickly became overwhelming and soon Sans could see nothing but white as he came hard with his brother's cock still pumping inside him.

"Slut." Papyrus chuckled as he stopped thrusting.

"n-no!" Sans pleaded, "don't stop! i want you to cum inside me! please!"

Papyrus blinked in surprise at him. It had evidently been the last thing he expected Sans to request of him and it managed to bring about a small blush on his cheeks. "you're absolutely filthy." He chastised but resumed fucking Sans all the same.

Sans threw his head back with a loud cry. He was overstimulated and the continued pleasure was making him lose his mind. A part of him firmly believe he would die from the ecstasy if it didn't stop soon – not that he wanted it to. Fucked to death was probably Sans's most ideal way to die. But all of that was quickly cast aside when Papyrus finally came, adding his cum to the filthy ectoplasmic liquids dirtying the water.

"ahhh…yes…" Sans sighed contently as he felt the sperm fill him.

"Is your heat feeling more tamed?" Papyrus asked as he pulled out.

Sans bit back the answer that immediately came to his mind and pondered it for a brief moment. "if i said no…would you fuck me again?"


End file.
